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phanboy_iv writes "Fans of both of the Raven classics, Heretic and Hexen, have been trying for almost a decade to convince Raven Software to release engine source code for the games under the GPL, much like the DOOM engine on which both of them are based. Well, they finally did it! Source code is available at Sourceforge. Both of these games have had the source available for a while, but under a restrictive license that hindered ports and modifications. Now, thanks to dedicated fans, that's no longer a problem."

And the result is... nothing. This is an old engine, and we have had better ones released under GPL already, such as that of Quake I/II and III. Lots of work has already gone to debugging the Doom, Quake I, and Quake III engine code, and I doubt anyone wants to start over and debug something that is similar to the Doom engine, but not debugged already, like prboom or chocolate doom.

You can't put code under the GPL that you don't have the right to put under the GPL. ZDoom's problem was that it was using non-GPL code, yet was made available according to the GNU General Public License.

ZDoom's problem was that it was using non-GPL code, yet was made available according to the GNU General Public License.

ZDoom's problem isn't that it was using non-GPL code, it was that it was trying to use GPL code: version 1.16 used the minilzo decompressor and Qmus2midi, and the whole thing was released as GPL. Version 1.22 had Qmus2midi ripped out, but minilzo was still there and there was nothing in the source indicating what license the whole thing could be distributed under. Well, we know now that it couldn't be distributed due to the mixing of Doom Source Licensed code with GPLed code (not to mention the Hexen bits that were in there), but I don't know what it claimed to be under at the time.

I don't have the source for any 2.0 versions except 2.0.96 handy. That one has no GPL code, although a few files have an exception that if they're used outside of ZDoom or one of its derivatives, then they fall under the GPL. The only piece of GPL code in GZDoom is Fragglescript, and the author of that has granted an exception so it can be linked with GZDoom. The author of GZDoom has put a lot of his own code under the LGPL, mostly to make it more difficult for closed-source ZDoom derivatives ZDaemon and Skulltag to use it...

ZDoom integrates code from BUILD for a number of purposes, including sloping floors, map format loading, graphics interpolation, and voxel support. Randy Heit reworked code from Ken Silverman's demo game KBUILD rather than rewriting these features himself for ZDoom. The problem is, KBUILD is still only released under the proprietary BUILD licence, which is fairly flexible, but not GPL compatible. Duke 3D, however, contains the same sloping floor support, map format loading, and graphics interpolation that K

Actually, let me re-re-re-correct that. Since the code for Shadow Warrior is released (which does, in fact, have Ken Silverman's voxel code in it) pretty much the entire collection of features that ZDoom took from BUILD are now available from GPLed codebases derived from the core BUILD tree. The open-sourcing of Hexen and Heretic is the last step, unless code from Strife was integrated without a license (but I think that was reverse-engineered.)

Same thing happened with Doom. It ended up being ported to Linux first (when it was fixed to use a more freely available sound library) and then ported back to DOS with the fixed sound code, giving birth to the general use of the term "source port" to mean any derivative. I imagine the code could just be cut and pasted, since there's no difference in capabilities—and, also, many of the modern ports use FMOD now, anyway.

Yeah, just reading about that now. I found this [wikia.com] on the Doom Wiki an interesting read. I think you're right about the "copy and paste" (maybe a *little* more complicated than that, but not much seeing as the ground work has already been done by the Doom porting people).

If I've learned anything from my time on Slashdot, it's that there's a community for everything. No matter how weird or insignificant a software project is, there will be a dedicated community around it.

The interesting parts are not the engine, really - Doom has been open source for ages now, and all the extras that were in Heretic & Hexen on top of that (such as hacked looking up/down, animated walls, and scripting) were reimplemented from scratch by the community anyway.

What's interesting is the actual game logic. If someone is up to recreate an up-to-date faithful-recreation port of Heretic or Hexen, they now know precisely how the AI is supposed to react, what are the speed and damage of the proj

They do, but it wasn't technically legal to redistribute their code under the GPL. ZDoom still has this problem with Ken Silverman's BUILD engine, which uses its own license (Randy Heit lifted slope code and uncapped frame rate stuff from it, amongst other things.)

Not entirely. Some are capable of playing the levels but without an inventory, others are reverse engineering the inventory, but they don't work quite right. Having the source released under the GPL will mean either better full support in existing engines, or good 1:1 source ports. Likely both.

The source was already released out into the open, but under a weird license. Ports like ZDaemon have problems with the inventory system because they're based on versions of ZDoom when the inventory system was still being implemented (1.22 and various betas of 1.23)

This release is of monumental importance, as it will allow GPL Doom source ports to freely integrate support for Heretic and Hexen without requiring the code to be rewritten from scratch or to be emulated through empirical testing. The door is also now open for new ports such as "Chocolate" Heretic and Hexen, and for such ports to be distributed in free software packages.

I'm not sure if they mean "monumental" in the sense of old tombstones, but there you go.

I didn't see it mentioned -- does this include the WAD (as in Johnny Wad) files? I think it's good that they released the source code in the first place, and even better that it's now under a standard license... but is it really useful for anything? Anyhow, thanks guys!

Does anyone know if you ACTUALLY get these games? Or are you forever tied to playing them through a Steam account and you have to be on the internets? I realize, for this conversation, you can snag the WAD files off your drive but I'm talking about the other games. I'd like to have a few on hand while traveling and not hooked up to the cyber world.

I haven't bought them, but ISTR that you get the EXEs, WADs, etc. and the original DOS executable runs inside DOSBox, which is included with your Steam download.

The DOSBox thing of course doesn't apply with the Windows games included with the package. No idea how the Steam DRM stuff works with those.

Generally, though, when you travel and are away from an Internet connection, you just have to install Steam on your laptop, log into your account, download your games completely, and then you don't need the Int

True. I went more of the "middle finger" route on Doom-Quake wads/paks since I bought all those games once, long ago, and have since lost the install media.

But, I was just speaking of game art in general. I've seen one project stick mostly with "coder art" (noooo) because everyone he interviews wants to forever own rights to a few pixels, thus hindering the free distribution of a package.

I'm guessing it has something to do with what their teachers told them at the art institute or whatever. Because the only

The biggest fear for artists is their work getting quietly used without their consent. They're the only ones who are there to notice or stand up for it, as well. The open source movement is established enough that there's some level of protection and attribution. In art, everyone depends on people knowing that this work IS yours, belongs to you, and must purchase the license from you directly. Simply making art is not as profitable as writing code- if an open source model were applied to art, a field where

Creative Commons licenses are good for art, text and music. But the major flaw with art is that everything ends up looking the same. Voices are distinctive enough to tell who sang a song, and even writing styles are distinctive enough to let someone tell who wrote the book. But for art everything ends up looking the same for all but the biggest fans of an artist.

The source is really the important thing here. I believe you can still buy all of those games still as part of a collection or second hand.

Having the source means that the software needed to run the game files can be ported to whatever platform is necessary and fixed. It also means that freeware level packs are useful even without paying for the game.

Still, it would be nice if the WADs and such were included as well. But this is pretty significant to a lot of people.

I believe you can still buy all of those games still as part of a collection or second hand.

All Doom games, Heretic, and both Hexen games are available on Steam individually, as parts of the id Super Pack [steampowered.com], or as parts of the Doom [steampowered.com] and Heretic+Hexen [steampowered.com] packs. You don't need to play them as packaged on Steam, of course (they just packaged the original games into DOSBox) - just buy them, take the.wad files, and use with ZDoom.

Useful for anything? Are you serious? There are tons of Doom engine source ports out there, and if you're looking for the IWADs, all Doom engine games are available on Steam for a few bucks so it's not like they're hard to find.

i picked up the collectors edition from wally world for $10, the included doom95 engine worked but the newer engines looked better (i prefer the mix of old sprites for monsters and new 3d packs for ordinance and weapons, the 3d models for the monsters were horrible last time i checked

Many of the Doom source modifications out there use code from the Heretic and Hexen source bases in order to create a combined port that can support all games, and support the additional engine features that were brought by Hexen in the older games.

However since the Doom source is GPL while the Heretic and Hexen code bases were not, any project doing so was actively violating the GPL, until now.

Now hopefully there will be true Heretic and Hexen support in PrBoom. Vavoom didn't run Heretic and Hexen right. ZDoom and ZDaemon meant I had to run them under Wine. (Bad memories about argueing with Nightfang about how much he 'hated Linux' and 'Didn't want Linux users playing ZDaemon.'